Supercontinent Symposium 2012
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LIBRO GEOLOGIA 30.Qxd:Maquetaciûn 1
Trabajos de Geología, Universidad de Oviedo, 29 : 278-283 (2010) From ductile to brittle deformation – the structural development and strain variations along a crustal-scale shear zone in SW Finland T. TORVELA1* AND C. EHLERS1 1Åbo Akademi University, Department of geology and mineralogy, Tuomiokirkontori 1, 20500 Turku, Finland. *e-mail: [email protected] Abstract: This study demonstrates the impact of variations in overall crustal rheology on crustal strength in relatively high P-T conditions at mid- to lower mid-crustal levels. In a crustal-scale shear zone, along-strike variations in the rheological competence result in large-scale deformation partition- ing and differences in the deformation style and strain distribution. Keywords: shear zone, deformation, strain partitioning, terrane boundary, Finland, Palaeoproterozoic. The structural behaviour of the crustal-scale Sottunga- several orogenic periods from the Archaean to the Jurmo shear zone (SJSZ) in SW Finland is described. Caledonian orogen 450-400 Ma ago (Fig. 1; e.g. The shear zone outlines a significant crustal disconti- Nironen, 1997; Lahtinen et al., 2005). The bulk of nuity, and it probably also represents a terrain bound- the shield (central and southern Finland, central and ary between the amphibolite-to-granulite facies, dome- northern Sweden) was formed during the and-basin-style crustal block to the north and the Palaeoproterozoic orogeny, ca. 2.0-1.85 Ga ago, amphibolite facies rocks with dominantly steeply dip- which is often referred to in literature as the ping structures to the south. The results of this study Svecofennian orogeny (Gaál and Gorbatschev, 1987). also imply that the late ductile structures (~1.80-1.79 The main direction of convergence against the Ga) can be attributed to the convergence of an Archaean nucleus to the NE (Fig. -
Kinematic Reconstruction of the Caribbean Region Since the Early Jurassic
Earth-Science Reviews 138 (2014) 102–136 Contents lists available at ScienceDirect Earth-Science Reviews journal homepage: www.elsevier.com/locate/earscirev Kinematic reconstruction of the Caribbean region since the Early Jurassic Lydian M. Boschman a,⁎, Douwe J.J. van Hinsbergen a, Trond H. Torsvik b,c,d, Wim Spakman a,b, James L. Pindell e,f a Department of Earth Sciences, Utrecht University, Budapestlaan 4, 3584 CD Utrecht, The Netherlands b Center for Earth Evolution and Dynamics (CEED), University of Oslo, Sem Sælands vei 24, NO-0316 Oslo, Norway c Center for Geodynamics, Geological Survey of Norway (NGU), Leiv Eirikssons vei 39, 7491 Trondheim, Norway d School of Geosciences, University of the Witwatersrand, WITS 2050 Johannesburg, South Africa e Tectonic Analysis Ltd., Chestnut House, Duncton, West Sussex, GU28 OLH, England, UK f School of Earth and Ocean Sciences, Cardiff University, Park Place, Cardiff CF10 3YE, UK article info abstract Article history: The Caribbean oceanic crust was formed west of the North and South American continents, probably from Late Received 4 December 2013 Jurassic through Early Cretaceous time. Its subsequent evolution has resulted from a complex tectonic history Accepted 9 August 2014 governed by the interplay of the North American, South American and (Paleo-)Pacific plates. During its entire Available online 23 August 2014 tectonic evolution, the Caribbean plate was largely surrounded by subduction and transform boundaries, and the oceanic crust has been overlain by the Caribbean Large Igneous Province (CLIP) since ~90 Ma. The consequent Keywords: absence of passive margins and measurable marine magnetic anomalies hampers a quantitative integration into GPlates Apparent Polar Wander Path the global circuit of plate motions. -
Playing Jigsaw with Large Igneous Provinces a Plate Tectonic
PUBLICATIONS Geochemistry, Geophysics, Geosystems RESEARCH ARTICLE Playing jigsaw with Large Igneous Provinces—A plate tectonic 10.1002/2015GC006036 reconstruction of Ontong Java Nui, West Pacific Key Points: Katharina Hochmuth1, Karsten Gohl1, and Gabriele Uenzelmann-Neben1 New plate kinematic reconstruction of the western Pacific during the 1Alfred-Wegener-Institut Helmholtz-Zentrum fur€ Polar- und Meeresforschung, Bremerhaven, Germany Cretaceous Detailed breakup scenario of the ‘‘Super’’-Large Igneous Province Abstract The three largest Large Igneous Provinces (LIP) of the western Pacific—Ontong Java, Manihiki, Ontong Java Nui Ontong Java Nui ‘‘Super’’-Large and Hikurangi Plateaus—were emplaced during the Cretaceous Normal Superchron and show strong simi- Igneous Province as result of larities in their geochemistry and petrology. The plate tectonic relationship between those LIPs, herein plume-ridge interaction referred to as Ontong Java Nui, is uncertain, but a joined emplacement was proposed by Taylor (2006). Since this hypothesis is still highly debated and struggles to explain features such as the strong differences Correspondence to: in crustal thickness between the different plateaus, we revisited the joined emplacement of Ontong Java K. Hochmuth, [email protected] Nui in light of new data from the Manihiki Plateau. By evaluating seismic refraction/wide-angle reflection data along with seismic reflection records of the margins of the proposed ‘‘Super’’-LIP, a detailed scenario Citation: for the emplacement and the initial phase of breakup has been developed. The LIP is a result of an interac- Hochmuth, K., K. Gohl, and tion of the arriving plume head with the Phoenix-Pacific spreading ridge in the Early Cretaceous. The G. -
Metamorphic Evolution of Relict Eclogite-Facies Rocks in the Paleoproterozoic Nagssugtoqidian Orogen, South-East Greenland”
“Metamorphic evolution of relict eclogite-facies rocks in the Paleoproterozoic Nagssugtoqidian Orogen, South-East Greenland” Von der Fakultät für Georessourcen und Materialtechnik der Rheinisch-Westfälischen Technischen Hochschule Aachen zur Erlangung des akademischen Grades eines Doktors der Naturwissenschaften genehmigte Dissertation vorgelegt von M.Sc. Geowissenschaften Sascha Müller aus Münster Berichter: PD Annika Dziggel Ph.D. Prof. Dr. Jochen Kolb Tag der mündlichen Prüfung: 14. Dezember 2018 Diese Dissertation ist auf den Internetseiten der Universitätsbibliothek online verfügbar. Foreword and Acknowledgements The following thesis was written over the course of 5 years, starting in August 2013, in the framework of the joint GEUS-MMR “SEGMENT (South-East Greenland Mineral Endowment Task)”-project. During the course of this study, I had the opportunity to witness the beautiful scenery and outstanding geology of Greenland firsthand during a one-month fieldtrip to the area around Tasiilaq in June and August of 2014, for which I greatly appreciate funding by the Geological Survey of Denmark and Greenland (GEUS) and the Ministry of Mineral Resources of Greenland (MMR). Regular funding was provided by the Deutsche Forschungsgemeinschaft from 2013 to 2016, with additional funding until late 2017 by employment at the Institute of Applied Mineralogy and Economic Geology at RWTH Aachen. At first, I want to thank my supervisor Annika Dziggel for her great support and guidance, but also for initiating this interesting project in the first place. Thank you for your support during fieldwork, for encouraging me to keep a sharp mind during analysis and interpretation and for teaching me how to properly present my data. Many thanks also go out to my Co-Supervisor Sven Sindern for his support during the countless hours I spent in the laboratory, as well as with the whole-rock data and isotopic dating. -
Plate Tectonic Regulation of Global Marine Animal Diversity
Plate tectonic regulation of global marine animal diversity Andrew Zaffosa,1, Seth Finneganb, and Shanan E. Petersa aDepartment of Geoscience, University of Wisconsin–Madison, Madison, WI 53706; and bDepartment of Integrative Biology, University of California, Berkeley, CA 94720 Edited by Neil H. Shubin, The University of Chicago, Chicago, IL, and approved April 13, 2017 (received for review February 13, 2017) Valentine and Moores [Valentine JW, Moores EM (1970) Nature which may be complicated by spatial and temporal inequities in 228:657–659] hypothesized that plate tectonics regulates global the quantity or quality of samples (11–18). Nevertheless, many biodiversity by changing the geographic arrangement of conti- major features in the fossil record of biodiversity are consis- nental crust, but the data required to fully test the hypothesis tently reproducible, although not all have universally accepted were not available. Here, we use a global database of marine explanations. In particular, the reasons for a long Paleozoic animal fossil occurrences and a paleogeographic reconstruction plateau in marine richness and a steady rise in biodiversity dur- model to test the hypothesis that temporal patterns of continen- ing the Late Mesozoic–Cenozoic remain contentious (11, 12, tal fragmentation have impacted global Phanerozoic biodiversity. 14, 19–22). We find a positive correlation between global marine inverte- Here, we explicitly test the plate tectonic regulation hypothesis brate genus richness and an independently derived quantitative articulated by Valentine and Moores (1) by measuring the extent index describing the fragmentation of continental crust during to which the fragmentation of continental crust covaries with supercontinental coalescence–breakup cycles. The observed posi- global genus-level richness among skeletonized marine inverte- tive correlation between global biodiversity and continental frag- brates. -
Paleomagnetism and U-Pb Geochronology of the Late Cretaceous Chisulryoung Volcanic Formation, Korea
Jeong et al. Earth, Planets and Space (2015) 67:66 DOI 10.1186/s40623-015-0242-y FULL PAPER Open Access Paleomagnetism and U-Pb geochronology of the late Cretaceous Chisulryoung Volcanic Formation, Korea: tectonic evolution of the Korean Peninsula Doohee Jeong1, Yongjae Yu1*, Seong-Jae Doh2, Dongwoo Suk3 and Jeongmin Kim4 Abstract Late Cretaceous Chisulryoung Volcanic Formation (CVF) in southeastern Korea contains four ash-flow ignimbrite units (A1, A2, A3, and A4) and three intervening volcano-sedimentary layers (S1, S2, and S3). Reliable U-Pb ages obtained for zircons from the base and top of the CVF were 72.8 ± 1.7 Ma and 67.7 ± 2.1 Ma, respectively. Paleomagnetic analysis on pyroclastic units yielded mean magnetic directions and virtual geomagnetic poles (VGPs) as D/I = 19.1°/49.2° (α95 =4.2°,k = 76.5) and VGP = 73.1°N/232.1°E (A95 =3.7°,N =3)forA1,D/I = 24.9°/52.9° (α95 =5.9°,k =61.7)and VGP = 69.4°N/217.3°E (A95 =5.6°,N=11) for A3, and D/I = 10.9°/50.1° (α95 =5.6°,k = 38.6) and VGP = 79.8°N/ 242.4°E (A95 =5.0°,N = 18) for A4. Our best estimates of the paleopoles for A1, A3, and A4 are in remarkable agreement with the reference apparent polar wander path of China in late Cretaceous to early Paleogene, confirming that Korea has been rigidly attached to China (by implication to Eurasia) at least since the Cretaceous. The compiled paleomagnetic data of the Korean Peninsula suggest that the mode of clockwise rotations weakened since the mid-Jurassic. -
1 Introduction Gondwana
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Sydney eScholarship Regional plate tectonic reconstructions of the Indian Ocean Thesis Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy Ana Gibbons School of Geosciences 2012 Supervised by Professor R. Dietmar Müller and Dr Joanne Whittaker The University of Sydney, PhD Thesis, Ana Gibbons, 2012 - Introduction DECLARATION I declare that this thesis contains less than 100,000 words and contains no work that has been submitted for a higher degree at any other university or institution. No animal or ethical approvals were applicable to this study. The use of any published written material or data has been duly acknowledged. Ana Gibbons ii The University of Sydney, PhD Thesis, Ana Gibbons, 2012 - Introduction ACKNOWLEDGEMENTS I would like to thank my supervisors for their endless encouragement, generosity, patience, and not least of all their expertise and ingenuity. I have thoroughly benefitted from working with them and cannot imagine a better supervisory team. I also thank Maria Seton, Carmen Gaina and Sabin Zahirovic for their help and encouragement. I thank Statoil (Norway), the Petroleum Exploration Society of Australia (PESA) and the School of Geosciences, University of Sydney for support. I am extremely grateful to Udo Barckhausen, Kaj Hoernle, Reinhard Werner, Paul Van Den Bogaard and all staff and crew of the CHRISP research cruise for a very informative and fun collaboration, which greatly refined this first chapter of this thesis. I also wish to thank Dr Yatheesh Vadakkeyakath from the National Institute of Oceanography, Goa, India, for his thorough review, which considerably improved the overall model and quality of the second chapter. -
Precambrian Basement and Late Paleoproterozoic to Mesoproterozoic Tectonic Evolution of the SW Yangtze Block, South China
minerals Article Precambrian Basement and Late Paleoproterozoic to Mesoproterozoic Tectonic Evolution of the SW Yangtze Block, South China: Constraints from Zircon U–Pb Dating and Hf Isotopes Wei Liu 1,2,*, Xiaoyong Yang 1,*, Shengyuan Shu 1, Lei Liu 1 and Sihua Yuan 3 1 CAS Key Laboratory of Crust-Mantle Materials and Environments, University of Science and Technology of China, Hefei 230026, China; [email protected] (S.S.); [email protected] (L.L.) 2 Chengdu Center, China Geological Survey, Chengdu 610081, China 3 Department of Earthquake Science, Institute of Disaster Prevention, Langfang 065201, China; [email protected] * Correspondence: [email protected] (W.L.); [email protected] (X.Y.) Received: 27 May 2018; Accepted: 30 July 2018; Published: 3 August 2018 Abstract: Zircon U–Pb dating and Hf isotopic analyses are performed on clastic rocks, sedimentary tuff of the Dongchuan Group (DCG), and a diabase, which is an intrusive body from the base of DCG in the SW Yangtze Block. The results provide new constraints on the Precambrian basement and the Late Paleoproterozoic to Mesoproterozoic tectonic evolution of the SW Yangtze Block, South China. DCG has been divided into four formations from the bottom to the top: Yinmin, Luoxue, Heishan, and Qinglongshan. The Yinmin Formation, which represents the oldest rock unit of DCG, was intruded by a diabase dyke. The oldest zircon age of the clastic rocks from the Yinmin Formation is 3654 Ma, with "Hf(t) of −3.1 and a two-stage modeled age of 4081 Ma. Another zircon exhibits an age of 2406 Ma, with "Hf(t) of −20.1 and a two-stage modeled age of 4152 Ma. -
Where Is (And Was) Pennsylvania?”
Essay: “Where Is (and Was) Pennsylvania?” W.E. Hamilton D.Y. Sillman Penn State University This work is licensed under a Creative Commons Attribution‐Noncommercial‐No Derivative Works 3.0 license. It may be distributed and shared, with attribution, but not altered or used commercially in any way. “Where Is (and Was) Pennsylvania?” Pennsylvania is a pretty obvious place to us. It’s a rectangular, politically defined piece of the eastern United States with a wiggly eastern border that follows the Delaware River and three, very straight other borders on the north, west, and south that were laboriously marked off after a great deal of social and legal travail and even some violence. It’s a hilly to mountainous, river‐rich place with forests and fields and cities. Its statistics are simple: it is about three hundred miles from east to west and a little less than one hundred and seventy miles from south to north. It comprises 46,058 square miles (although the number “45,308” shows up in some references). Its latitude range is thirty‐nine degrees forty‐three minutes N to forty‐two degrees N, and its longitude range is seventy‐four degrees and forty‐three minutes W to eighty degrees thirty‐one minutes W (Netstate 2008). This Pennsylvania, though, hasn’t always been all of that. The great rectangle of Pennsylvania has been, through the geological history of the Earth, in the southern hemisphere, on the equator, and in a great many places in between. It has been oriented with its long, three hundred mile axis east to west and also with this long axis running south to north. -
Ages of Detrital Zircons (U/Pb, LA-ICP-MS) from the Latest
Precambrian Research 244 (2014) 288–305 Contents lists available at ScienceDirect Precambrian Research jo urnal homepage: www.elsevier.com/locate/precamres Ages of detrital zircons (U/Pb, LA-ICP-MS) from the Latest Neoproterozoic–Middle Cambrian(?) Asha Group and Early Devonian Takaty Formation, the Southwestern Urals: A test of an Australia-Baltica connection within Rodinia a,∗ b c Nikolay B. Kuznetsov , Joseph G. Meert , Tatiana V. Romanyuk a Geological Institute, Russian Academy of Sciences, Pyzhevsky Lane, 7, Moscow 119017, Russia b Department of Geological Sciences, University of Florida, 355 Williamson Hall, Gainesville, FL 32611, USA c Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, B. Gruzinskaya ul. 10, Moscow 123810, Russia a r t i c l e i n f o a b s t r a c t Article history: A study of U-Pb ages on detrital zircons derived from sedimentary sequences in the western flank of Received 5 February 2013 Urals (para-autochthonous or autochthonous with Baltica) was undertaken in order to ascertain/test Received in revised form source models and paleogeography of the region in the Neoproterozoic. Samples were collected from the 16 September 2013 Ediacaran-Cambrian(?) age Asha Group (Basu and Kukkarauk Formations) and the Early Devonian-aged Accepted 18 September 2013 Takaty Formation. Available online 19 October 2013 Ages of detrital zircons within the Basu Formation fall within the interval 2900–700 Ma; from the Kukkarauk Formation from 3200 to 620 Ma. Ages of detrital zircons from the Devonian age Takaty For- Keywords: Australia mation are confined to the Paleoproterozoic and Archean (3050–1850 Ma). -
295-309 Elsevier Science Publishers BV, Amsterdam 295 the Late
Precambrian Research, 64 (1993) 295-309 295 Elsevier Science Publishers B.V., Amsterdam The late Svecofennian granite-migmatite zone of southern Finland—a belt of transpressive deformation and granite emplacement Carl Ehlers*, Alf Lindroos and Olavi Selonen Department of Geology and Mineralogy, Abo Akademi University, SF-20500 Abo, Finland Received March 21, 1991; revised version accepted November 3,1992 ABSTRACT The late Svecofennian granite-migmatite (LSGM) zone in southwestern Finland is a ~ 100 km wide and 500 km long belt transecting the southern Svecofennides from WSW to ENE. It was formed in an area of thin pillow lavas, volcaniclastic sediments and limestones. The area is interpreted as having been an early basin of crustal extension which was the locus of an inherited zone of weakness in the Proterozoic crust. Early recumbent folding was followed by crustal thickening and intrusions of ~ 1.89-1.8 8 Ga old plutonics. The LSGM-zone is characterized by 1.84-1.83 Ga old rhomboidal sheets of late Svecofennian microcline granite and is bounded by ductile shears. Amongst the two major phases of deformation defined in the LSGM-zone, the earlier one (Dl) affected only the supracmstals and the 1.89-1.88 Ga old early plutonics. In contrast, the later phase (D2) also deformed the late Svecofennian migmatites and granites. Dl represents a complex and long-lasting deformation event which in- cluded overturning and thrusting of the Svecofennian strata. D2 comprised ENE-WSW directed drag accompanied by NNW-SSE compression. The Svecofennian crust was thick- ened further and anatectic microcline granites intruded along thrusts. -
Finnish Lithosphere Meeting
INSTITUTE OF SEISMOLOGY UNIVERSITY OF HELSINKI REPORT S-65 LITHOSPHERE 2016 NINTH SYMPOSIUM ON THE STRUCTURE, COMPOSITION AND EVOLUTION OF THE LITHOSPHERE IN FENNOSCANDIA Geological Survey of Finland, Espoo, November 9-11, 2016 PROGRAMME AND EXTENDED ABSTRACTS edited by Ilmo Kukkonen, Suvi Heinonen, Kati Oinonen, Katriina Arhe, Olav Eklund, Fredrik Karell, Elena Kozlovskaya, Arto Luttinen, Raimo Lahtinen, Juha Lunkka, Vesa Nykänen, Markku Poutanen, Eija Tanskanen and Timo Tiira Helsinki 2016 INSTITUTE OF SEISMOLOGY UNIVERSITY OF HELSINKI REPORT S-65 LITHOSPHERE 2016 NINTH SYMPOSIUM ON STRUCTURE, COMPOSITION AND EVOLUTION OF THE LITHOSPHERE IN FENNOSCANDIA PROGRAMME AND EXTENDED ABSTRACTS Edited by Ilmo Kukkonen, Suvi Heinonen, Kati Oinonen, Katriina Arhe, Olav Eklund, Fredrik Karell, Elena Kozlovskaya, Arto Luttinen, Raimo Lahtinen, Juha Lunkka, Vesa Nykänen, Markku Poutanen, Eija Tanskanen and Timo Tiira Geological Survey of Finland, Espoo, November 9-11, 2016 Helsinki 2016 Series Editor-in-Chief: Annakaisa Korja Guest Editors: Ilmo Kukkonen, Suvi Heinonen, Kati Oinonen, Katriina Arhe, Olav Eklund, Fredrik Karell, Elena Kozlovskaya, Arto Luttinen, Raimo Lahtinen, Juha Lunkka, Vesa Nykänen, Markku Poutanen, Eija Tanskanen and Timo Tiira Publisher: Institute of Seismology P.O. Box 68 FI-00014 University of Helsinki Finland Phone: +358-294-1911 (switchboard) http://www.helsinki.fi/geo/seismo/ ISSN 0357-3060 ISBN 978-952-10-5081-7 (Paperback) Helsinki University Print Helsinki 2016 ISBN 978-952-10-9282-5 (PDF) i LITHOSPHERE 2016 NINTH SYMPOSIUM